| Summary: | During LGM the margins of the Greenland ice sheet around the whole perimeter stood on the shelf – but where? The first estimates had to be based on evidence from land such as weathering limits on coastal mountains, major moraine belts, and altitudes of marine limits. Still the estimates ranged from inner to outer shelf, often under the assumption that the ice margin could not stop mid-shelf, and if it reached the shelf edge in one area, this should apply to the whole perimeter. Modelling, mainly on the basis of palaeoclimatic data, have presented a similar disparity between maximum and minimum estimates, assessing the Greenland ice sheet’s contribution to Holocene sea level rise - i.e. the difference in ice volume between LGM and now - to between 0.3 and 2.6 m. Recent years have given spectacular new insight into shelf-ice distribution and behaviour - especially by detailed seismic surveys on the shelf and cosmogenic isotope surface exposure dating on coastal mountains. Combining old and new evidence we present a new model on the ice distribution during LGM. The model is, as far as possible, based on tangible evidence and implies that different sectors of the ice sheet responded differently to climate change during and after LGM, and that coverage of the shelf may have been variable from one sector to another. Will the margin respond with similar complexity to global warming?
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